AN2001 Datasheet, PDF (1/20 Pages) Motorola, Inc – Designing Expansion Boards

Freescale Semiconductor, Inc.
MOTOROLA
SEMICONDUCTOR
APPLICATION NOTE
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AN2001/D
Designing Expansion Boards for the
Motorola MPC555EVB/ETAS ES200
by Randy Dees
Rev. 1, 31 July 2001
1 Introduction
The Motorola MPC555EVB/ETAS ES200 evaluation board was designed with multiple interfaces to al-
low flexibility for expansion. There are three sets of connectors for expansion. The MAPI-400+100 is on
the bottom side of the board and has access to all signals required to interface to a user application
board. The host communication expansion (HCE) connectors allow access to the bus of the MPC555.
The customized communication expansion (CCE) allows access to some of the MPC555 on-chip com-
munication ports. The HCE and the CCE are on the top side of the EVB555.
2 The Host Communication Expansion Connector (HCE)
The host communication expansion connectors on the EVB555 are designed for use as an expansion
of the external bus of the MPC555. They could be used to add additional memory or additional periph-
erals. There are two 60-pin connectors (CO106 – A and CO107 – B) part number Samtec TFM-130-12-
S-D-P. The matching connector required on the expansion board is SFM-130-02-S-D-P. The pin-out of
the HCE is shown in Table 1. The two connectors are mounted on 1.8 inch (45.72 mm) centers. This
allows for a board of approximately three square inches.
NOTE
An ETAS ETK interface may be mounted above the HCE board. The total height
(including the connectors on the EVB555 and all components on the HCE board)
must be below 0.6875 inches to allow clearance of the ETK board.
2.1 Memory Chips On The HCE
All 32 bits of the MPC555 data bus are available on the HCE connectors. Memory boards designed for
these connectors should use all 32 bits for the best performance. On a full-featured board, utilizing
memories less than 32 bits wide, the memory can be implemented with multiple chips. For 16-bit wide
memories, two chips should be used. Provisions should be made on the expansion board to allow the
second memory to be disabled to allow for smaller bus widths on the EVB555. 16-bit only memories
should be connected to D0-D15 of the data bus. CS[2] is available for use on the HCE board. If non-
volatile memories are used, CS[0] could also be used to allow for booting from the external memory. (It
is not possible to boot from the Texas Instruments TMS28F033 on the EVB555.) If CS[0] is used, the
TMS28F033 can be disabled by using the SGF_SEL signal on pin 160 of the ETK connector (CO508).
A logic high (default) enables the EVB555 on-board external flash memory. In addition, CSHCE could
be used if the chip timing is the same as used by the memory on the EVB555 and can fit in a 1-Mbyte
memory size.
This document contains information on a new product. Specifications and information herein are subject to change without notice.
© MOTOROLA INC., 2001
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